Re: Concord derailment, safe working and opinions.

[David Johnson <trainman@ozemail.com.au>]

Tell wrote:

> I can understand the need to change routes on the
> fly with a busy metro system as in Sydney due too
> "operational" needs, particularly during peaks.
> But, I am intrigued by the clogging up of the radio
> system.  Are there, that many changes.?  If the band
> waves can not handle them, what exactly are "normal"
> radio transmissions that take up so much band width.?
>

A transmission to a train from a signal box would almost certainly be done over the
simplex 450.050 MHz frequency, as many drivers still don't log their train radios in
properly.  Because of this, the signal box has one frequency to tell the diverging train
of the planned changes.  All the other trains in the area will hear this information which
doesn't concern them, and while it is being transmitted, the frequency becomes useless for
more important transmissions.  For example, Katoomba box can be heard in Wollongong.
Waterfall box can be heard at Hornsby.

> It is a mystery to a bushie like me that a short radio
> message to a particular train that is about to be
> diverted en route could not be squeezed in.

There really is no need for a simple changing of tracks.  If the destination is to be
changed, a transposition slip would be issued to the driver and guard prior to any
movements taking place.

--
David Johnson
CityRail Guard
trainman@ozemail.com.au
http://www.ozemail.com.au/~trainman/